[src/*]: Implement schedYield syscall

mogasergiu · Sep 28, 2021 · 9655e0d · 9655e0d
1 parent 31f171c
commit 9655e0d
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Showing 4 changed files with 19 additions and 3 deletions.
diff --git a/src/kernel/includes/task.hpp b/src/kernel/includes/task.hpp
@@ -112,6 +112,8 @@ namespace TASK {
             bool taskReady(uint8_t tid) const;
             void printPS() const;
     };
+
+    extern "C" void schedYield();
 }
 
 extern TASK::TaskMgr taskMgr;

diff --git a/src/kernel/interrupts/interrupts.cpp b/src/kernel/interrupts/interrupts.cpp
@@ -318,9 +318,7 @@ extern "C" long IntCallbacks::syscallISR(long arg1, ...) {
             break;
 
         case SYS_SCHED_YIELD:
-            TASK::acquireLock(&vgaHandler.vLock);
-            kpwarn("STUBBED!\n");
-            TASK::releaseLock(&vgaHandler.vLock);
+            TASK::schedYield();
 
             break;
 

diff --git a/src/kernel/task/task.cpp b/src/kernel/task/task.cpp
@@ -451,6 +451,21 @@ bool TaskMgr::taskReady(uint8_t tid) const {
     return this->tasks[tid] == NULL;
 }
 
+extern "C" void TASK::schedYield() {
+    uintptr_t eax, edx;
+    TASK::TaskHeader *task;
+
+    __asm__ __volatile__(
+        "rdmsr;"
+        : "=a" (eax), "=d" (edx)
+        : "c" (0xc0000101)
+    );
+
+    task = (TASK::TaskHeader*)((edx <<  32) + eax);
+
+    task->TCB->timeSlices = 0;  // yield
+}
+
 void TaskMgr::endTask(int8_t pid) {
     TaskHeader *task = NULL;
 

diff --git a/src/user/libc/syscalls.cpp b/src/user/libc/syscalls.cpp
@@ -97,6 +97,7 @@ extern "C" void* mmap(void *addr, size_t length, int prot) {
 extern "C" void schedYield() {
     __asm__ __volatile__(
         "int $0x80;"
+        "int $0x22;"
         :
         : "a" (SYS_SCHED_YIELD)
     );